Brake fluid leak: causes and solutions

It's no secret that brakes are an integral part of your car, because without them you won't be able to slow down or stop. But did you know that brake fluid is what keeps things running smoothly? If you notice a brake fluid leak, respond immediately! In this article, we will talk about the causes of a brake fluid leak and what to do if it happens to you!

🚗 What is brake fluid?

Brake fluid oil… yes yes it is oil, hydrocarbon, hc4. A fluid that is used in the braking system of cars. A synthetic product that is incompressible for the time allotted for its use. (which means that its volume must remain constant under the influence of external pressure) and are very insensitive to temperature changes. It becomes compressible due to the temperature at which steam is generated. It is a gas that, depending on the water content, brings the brake fluid to the boiling point. Due to temperature changes and the presence of water in the liquid, the latter loses its incompressible properties and requires replacement.

🇧🇷 What is brake fluid used for? 

Brake fluid is an integral part of a vehicle's braking system. This is even its essence. It performs the main function in the braking system. In fact, it is distributed through a hydraulic circuit and, thanks to the pressure on the pedal, transfers the braking force to the four wheels of the car. Stop Guaranteed!

🗓️ When to bleed the brake fluid?

The brake fluid must be pumped regularly, at least once every two years, otherwise the brake system will fail. and end up with, for example, brakes that no longer work.

Remember that brake fluid is hygroscopic, meaning it has the ability to absorb moisture from the air. When using the brakes, the brake pads rub against the brake discs and raise the temperature by several hundred degrees. This strong heat is transferred to the brake fluid. These changes in temperature and humidity will gradually degrade the brake fluid. Because brake fluid is hygroscopic, its boiling point drops significantly, from 230 ° C to 165 ° C. Repeated excessive braking mixes gas bubbles with the brake fluid and can damage the brakes. Therefore, it is necessary to regularly check the boiling point of the brake fluid by a specialist. This also applies to drum brakes.

As a rule, the brake fluid should be pumped every 50 kilometers. But above all, do not forget to change the brake fluid every time you replace the brakes.

The quality of the brake fluid is important. This can be verified using the DOT index, which classifies the fluid by its resistance to heat. For example, DOT 3 brake fluid is often composed of glycol and has a boiling point of 205 ° C.

🚘 Which brake fluid should you choose?

To choose between different brake fluids, follow your vehicle manufacturer's instructions in your owner's manual.

Here are the brake fluids you can deal with:

• mineral liquids = mainly used by Rolls Royce and Citroën on their older models, which use a single hydraulic system for suspension, steering, brakes and transmission.
• synthetic fluids = Made with glycol, meets US DOT standards as defined by the Department of Transportation. Depending on the standard provided to them and their appearance on the market in chronological order, they are designated as DOT 2, DOT 3, DOT 4, Super DOT 4, DOT 5.1.
• Dot 5 based on silicones = does not absorb moisture and therefore becomes more resistant over time.

The most commonly used brake fluids today are DOT 4, Super DOT 4 and DOT 5.1 for synthetic fluids and DOT 5 based on silicones. With the exception of DOT 2, DOT 3, DOT 4, Super DOT 4 and DOT 5.1 fluids are mixed together.

?? How to identify a brake fluid leak?

A brake fluid leak is reported on the dashboard of your vehicle. The indicator light representing the pedal will come on. After a long stop on the ground under the car, you will see a small challenge. The liquid is odorless and colorless.

You can also easily find leaks by regularly checking the brake fluid level. It costs you nothing and prevents any problems. Make sure the liquid level is between the minimum and maximum lines. If the level drops too quickly, don't wait to react.

Have you noticed a leak and want to measure its size? Put a newspaper under the car and see the amount of work.

🔧 What are the causes of brake fluid leaks?

Leaking brake fluid can cause brake failure - this is not a problem to be taken lightly.

The most common causes of leaks are:

• Bleed Screw Problem: The screws located on the brake calipers are used to remove excess fluid when servicing the brake system.
• defective master cylinder: this part directs the brake fluid to the brake system via hydraulic lines. If it is defective, fluid collects in the back of the engine compartment.
• defective wheel cylinder: you can see brake fluid on the sidewall of the tires.

?? What is the price for a replacement brake system?

If you notice a brake fluid leak, look where it is: in the back or front of your vehicle. Depending on the case, you can change the front or rear brake kit, depending on the location of the malfunction. Obviously, the price of this kit varies depending on your vehicle model. But count on an average of 200 €.

Here's an overview of the prices for the rear brake kit:

Now you have all the options for safe driving with good brake maintenance. If you have any questions, don't panic, Vroomly and its trusted garage assistants will take care of everything.